Genetic Phenomena Commons^™

Correcting Glucose-6-Phosphate Dehydrogenase Deficiency With A Small-Molecule Activator, Sunhee Hwang, Karen Mruk, Simin Rahighi, Andrew G. Raub, Che-Hong Chen, Lisa E. Dorn, Naoki Horikoshi, Soichi Wakatsuki, James K. Chen, Daria Mochly-Rosen

Pharmacy Faculty Articles and Research

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, one of the most common human genetic enzymopathies, is caused by over 160 different point mutations and contributes to the severity of many acute and chronic diseases associated with oxidative stress, including hemolytic anemia and bilirubin-induced neurological damage particularly in newborns. As no medications are available to treat G6PD deficiency, here we seek to identify a small molecule that corrects it. Crystallographic study and mutagenesis analysis identify the structural and functional defect of one common mutant (Canton, R459L). Using high-throughput screening, we subsequently identify AG1, a small molecule that increases the activity of the wild-type, the ...

All-In-One Adeno-Associated Virus Delivery And Genome Editing By Neisseria Meningitidis Cas9 In Vivo, Raed Ibraheim, Chun-Qing Song, Aamir Mir, Nadia Amrani, Wen Xue, Erik J. Sontheimer

RNA Therapeutics Institute Publications

BACKGROUND: Clustered, regularly interspaced, short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas) have recently opened a new avenue for gene therapy. Cas9 nuclease guided by a single-guide RNA (sgRNA) has been extensively used for genome editing. Currently, three Cas9 orthologs have been adapted for in vivo genome engineering applications: Streptococcus pyogenes Cas9 (SpyCas9), Staphylococcus aureus Cas9 (SauCas9), and Campylobacter jejuni (CjeCas9). However, additional in vivo editing platforms are needed, in part to enable a greater range of sequences to be accessed via viral vectors, especially those in which Cas9 and sgRNA are combined into a single vector genome.

RESULTS: Here ...

Nuclear Localization Of Huntingtin Mrna Is Specific To Cells Of Neuronal Origin, Marie C. Didiot, Chantal M. Ferguson, Socheata Ly, Andrew H. Coles, Abigail O. Smith, Alicia A. Bicknell, Lauren M. Hall, Ellen Sapp, Dimas Echeverria, Athma A. Pai, Marian Difiglia, Melissa J. Moore, Lawrence J. Hayward, Neil Aronin, Anastasia Khvorova

RNA Therapeutics Institute Publications

Huntington's disease (HD) is a monogenic neurodegenerative disorder representing an ideal candidate for gene silencing with oligonucleotide therapeutics (i.e., antisense oligonucleotides [ASOs] and small interfering RNAs [siRNAs]). Using an ultra-sensitive branched fluorescence in situ hybridization (FISH) method, we show that approximately 50% of wild-type HTT mRNA localizes to the nucleus and that its nuclear localization is observed only in neuronal cells. In mouse brain sections, we detect Htt mRNA predominantly in neurons, with a wide range of Htt foci observed per cell. We further show that siRNAs and ASOs efficiently eliminate cytoplasmic HTT mRNA and HTT protein, but ...

Numerous Recursive Sites Contribute To Accuracy Of Splicing In Long Introns In Flies, Athma A. Pai, Joseph M. Paggi, Paul Yan, Karen Adelman, Christopher B. Burge

Open Access Articles

Recursive splicing, a process by which a single intron is removed from pre-mRNA transcripts in multiple distinct segments, has been observed in a small subset of Drosophila melanogaster introns. However, detection of recursive splicing requires observation of splicing intermediates that are inherently unstable, making it difficult to study. Here we developed new computational approaches to identify recursively spliced introns and applied them, in combination with existing methods, to nascent RNA sequencing data from Drosophila S2 cells. These approaches identified hundreds of novel sites of recursive splicing, expanding the catalog of recursively spliced fly introns by 4-fold. A subset of recursive ...

An Asymmetric Centromeric Nucleosome, Yuichi Ichikawa, Noriko Saitoh, Paul D. Kaufman

Open Access Articles

Nucleosomes contain two copies of each core histone, held together by a naturally symmetric, homodimeric histone H3-H3 interface. This symmetry has complicated efforts to determine the regulatory potential of this architecture. Through molecular design and in vivo selection, we recently generated obligately heterodimeric H3s, providing a powerful tool for discovery of the degree to which nucleosome symmetry regulates chromosomal functions in living cells (Ichikawa et al., 2017). We now have extended this tool to the centromeric H3 isoform (Cse4/CENP-A) in budding yeast. These studies indicate that a single Cse4 N- or C-terminal extension per pair of Cse4 molecules is ...

Fatigue Associated With Rheumatoid Arthritis In Young Adults, Sydney Van Alstyne

Grace Peterson Nursing Research Colloquium

Background: Often, practitioners do not address their Rheumatoid Arthritis patients' fatigue and do not perceive it as a detriment to the patient's wellness. In actuality, fatigue has been determined to be proportionate to the other variables, such as pain and disease progression, of rheumatoid arthritis.

Objectives: to determine the cause(s) of fatigue in rheumatoid arthritis and determine how fatigue can be used in a clinical setting to determine disease progression and status in patients suffering from chronic illness.

Method: This integrative literature review was conducted using the keywords, “fatigue, rheumatoid arthritis, young adults, perception of fatigue” to search ...

Herpes Icp8 Protein Stimulates Homologous Recombination In Human Cells, Melvys Valledor, Richard S. Myers, Paul C. Schiller

Open Access Articles

Recombineering has transformed functional genomic analysis. Genome modification by recombineering using the phage lambda Red homologous recombination protein Beta in Escherichia coli has approached 100% efficiency. While highly efficient in E. coli, recombineering using the Red Synaptase/Exonuclease pair (SynExo) in other organisms declines in efficiency roughly correlating with phylogenetic distance from E. coli. SynExo recombinases are common to double-stranded DNA viruses infecting a variety of organisms, including humans. Human Herpes virus 1 (HHV1) encodes a SynExo comprised of ICP8 synaptase and UL12 exonuclease. In a previous study, the Herpes SynExo was reconstituted in vitro and shown to catalyze a ...

Drug-Resistance And Population Structure Of Plasmodium Falciparum Across The Democratic Republic Of Congo Using High-Throughput Molecular Inversion Probes, Ozkan Aydemir, Nicholas J. Hathaway, Patrick W. Marsh, Alice Tran, Thomas Reimonn, Jeffrey A. Bailey

Open Access Articles

A better understanding of the drivers of the spread of malaria parasites and drug resistance across space and time is needed. These drivers can be elucidated using genetic tools. Here, a novel molecular inversion probe (MIP) panel targeting all major drug-resistance mutations and a set of microsatellites was used to genotype Plasmodium falciparum infections of 552 children from the 2013-2014 Demographic and Health Survey conducted in the Democratic Republic of the Congo (DRC). Microsatellite-based analysis of population structure suggests that parasites within the DRC form a homogeneous population. In contrast, sulfadoxine-resistance markers in dihydropteroate synthase show marked spatial structure with ...

Deciphering The Role Of Human Arylamine N-Acetyltransferase 1 (Nat1) In Breast Cancer Cell Metabolism Using A Systems Biology Approach., Samantha Marie Carlisle

Electronic Theses and Dissertations

Background: Human arylamine N-acetyltransferase 1 (NAT1) is a phase II xenobiotic metabolizing enzyme found in almost all tissues. NAT1 can additionally hydrolyze acetyl-coenzyme A (acetyl-CoA) in the absence of an arylamine substrate. NAT1 expression varies inter-individually and is elevated in several cancers including estrogen receptor positive (ER+) breast cancers. Additionally, multiple studies have shown the knockdown of NAT1, by both small molecule inhibition and siRNA methods, in breast cancer cells leads to decreased invasive ability and proliferation and decreased anchorage-independent colony formation. However, the exact mechanism by which NAT1 expression affects cancer risk and progression remains unclear. Additionally, consequences ...

A Persistence Detector For Metabolic Network Rewiring In An Animal, Jote T. Bulcha, Gabrielle E. Giese, Zulfikar Ali, Yong-Uk Lee, Melissa D. Walker, Amy D. Holdorf, L. Safak Yilmaz, Robert C. Brewster, Albertha J. M. Walhout

University of Massachusetts Medical School Faculty Publications

Persistence detection is a mechanism that ensures a physiological output is only executed when the relevant input is sustained. Gene regulatory network circuits known as coherent type 1 feed forward loops (FFLs) with an AND-logic gate have been proposed to generate persistence detection. In such circuits two transcription factors (TFs) are both required to activate target genes and one of the two TFs activates the other. While numerous FFLs have been identified, examples of actual persistence detectors have only been described for bacteria. Here, we discover a transcriptional persistence detector in Caenorhabditis elegans involving the nuclear hormone receptors nhr-10 and ...

Llc Tumor Cells-Derivated Factors Reduces Adipogenesis In Co-Culture System, Magno Alves Lopes, Felipe Oliveira Franco, Felipe Henriques, Sidney Barnabe Peres, Miguel Luiz Batista Jr.

Open Access Articles

Cancer cachexia (CC) is a multifactorial syndrome with an unknown etiology. The primary symptom is the progressive reduction of the body weight. Recently, down-regulation of adipogenic and lipogenic genes were demonstrated to be early affected during cachexia progression in adipose tissue (AT), resulting in AT remodeling. Thus, this study aimed to evaluate in a co-culture system the influence of the Lewis Lung Carcinoma (LLC) tumor cells (c/c-LLC) in an established pre-adipocyte cell line 3T3-L1 adipogenic capacity. c/c-LLC in the presence of 3T3-L1 caused a reduction in lipids accumulation, suggesting that secretory tumor cells products may affect adipogenesis. Interestingly ...

Anril: A Lncrna At The Cdkn2a/B Locus With Roles In Cancer And Metabolic Disease, Yahui Kong, Chih-Heng Hsieh, Laura C. Alonso

Open Access Articles

The CDKN2A/B genomic locus is associated with risk of human cancers and metabolic disease. Although the locus contains several important protein-coding genes, studies suggest disease roles for a lesser-known antisense lncRNA encoded at this locus, called ANRIL. ANRIL is a complex gene containing at least 21 exons in simians, with many reported linear and circular isoforms. Like other genes, abundance of ANRIL is regulated by epigenetics, classic transcription regulation, splicing, and post-transcriptional influences such as RNA stability and microRNAs. Known molecular functions of ANRIL include in cis and in trans gene regulation through chromatin modification complexes, and influence over ...

Extending Chemical Perturbations Of The Ubiquitin Fitness Landscape In A Classroom Setting Reveals New Constraints On Sequence Tolerance, David Mavor, Daniel N. Bolon, Martin Kampmann, James S. Fraser

Open Access Articles

Although the primary protein sequence of ubiquitin (Ub) is extremely stable over evolutionary time, it is highly tolerant to mutation during selection experiments performed in the laboratory. We have proposed that this discrepancy results from the difference between fitness under laboratory culture conditions and the selective pressures in changing environments over evolutionary timescales. Building on our previous work (Mavor et al., 2016), we used deep mutational scanning to determine how twelve new chemicals (3-Amino-1,2,4-triazole, 5-fluorocytosine, Amphotericin B, CaCl2, Cerulenin, Cobalt Acetate, Menadione, Nickel Chloride, p-Fluorophenylalanine, Rapamycin, Tamoxifen, and Tunicamycin) reveal novel mutational sensitivities of ubiquitin residues. Collectively, our ...

Dynamic Placement Of The Linker Histone H1 Associated With Nucleosome Arrangement And Gene Transcription In Early Drosophila Embryonic Development, Jian Hu, Liang Gu, Youqiong Ye, Meizhu Zheng, Zhu Xu, Jing Lin, Yanhua Du, Mengxue Tian, Lifang Luo, Beibei Wang, Xiaobai Zhang, Zhiping Weng, Cizhong Jiang

Open Access Articles

The linker histone H1 is critical to maintenance of higher-order chromatin structures and to gene expression regulation. However, H1 dynamics and its functions in embryonic development remain unresolved. Here, we profiled gene expression, nucleosome positions, and H1 locations in early Drosophila embryos. The results show that H1 binding is positively correlated with the stability of beads-on-a-string nucleosome organization likely through stabilizing nucleosome positioning and maintaining nucleosome spacing. Strikingly, nucleosomes with H1 placement deviating to the left or the right relative to the dyad shift to the left or the right, respectively, during early Drosophila embryonic development. H1 occupancy on genic ...

Association Tests For Genetic Effect And Its Interaction With Environmental Factors, Zhengyang Zhou

Statistical Science Theses and Dissertations

My research is in the area of statistical genetics, and it contains three projects: (1) Differentiating the Cochran-Armitage (CA) trend test and Pearson’s chi-square test: location and dispersion; (2) Decomposing Pearson’s chi-square test: a linear regression and its departure from linearity; (3) Testing nonlinear gene-environment (GxE) interaction through varying coefficient and linear mixed models.

(1) In genetic case-control association studies, a standard practice is to perform the CA trend test with 1 degree-of-freedom (df) under the assumption of an additive model. However, when the true genetic model is recessive or near recessive, it is outperformed by Pearson’s ...

Crystal Structure Of The Catalytic Domain Of Hiv-1 Restriction Factor Apobec3g In Complex With Ssdna, Atanu Maiti, Wazo Myint, Tapan Kanai, Krista Delviks-Frankenberry, Christina Sierra Rodriguez, Vinay K. Pathak, Celia A. Schiffer, Hiroshi Matsuo

Open Access Articles

The human APOBEC3G protein is a cytidine deaminase that generates cytidine to deoxy-uridine mutations in single-stranded DNA (ssDNA), and capable of restricting replication of HIV-1 by generating mutations in viral genome. The mechanism by which APOBEC3G specifically deaminates 5'-CC motifs has remained elusive since structural studies have been hampered due to apparently weak ssDNA binding of the catalytic domain of APOBEC3G. We overcame the problem by generating a highly active variant with higher ssDNA affinity. Here, we present the crystal structure of this variant complexed with a ssDNA substrate at 1.86 A resolution. This structure reveals atomic-level interactions ...

Tale Factors Use Two Distinct Functional Modes To Control An Essential Zebrafish Gene Expression Program, Franck Ladam, William Stanney, Ian J. Donaldson, Ozge Yildiz, Nicoletta Bobola, Charles G. Sagerstrom

Open Access Articles

TALE factors are broadly expressed embryonically and known to function in complexes with transcription factors (TFs) like Hox proteins at gastrula/segmentation stages, but it is unclear if such generally expressed factors act by the same mechanism throughout embryogenesis. We identify a TALE-dependent gene regulatory network (GRN) required for anterior development and detect TALE occupancy associated with this GRN throughout embryogenesis. At blastula stages, we uncover a novel functional mode for TALE factors, where they occupy genomic DECA motifs with nearby NF-Y sites. We demonstrate that TALE and NF-Y form complexes and regulate chromatin state at genes of this GRN ...

A Rationally Engineered Capsid Variant Of Aav9 For Systemic Cns-Directed And Peripheral Tissue-Detargeted Gene Delivery In Neonates, Dan Wang, Shaoyong Li, Dominic J. Gessler, Jun Xie, Li Zhong, Jia Li, Karen Tran, Kim Van Vliet, Lingzhi Ren, Qin Su, Ran He, Jason E. Goetzmann, Terence R. Flotte, Mavis Agbandje-Mckenna, Guangping Gao

Open Access Articles

Adeno-associated virus (AAV) has provided the gene therapy field with the most powerful in vivo gene delivery vector to realize safe, efficacious, and sustainable therapeutic gene expression. Because many clinically relevant properties of AAV-based vectors are governed by the capsid, much research effort has been devoted to the development of AAV capsids for desired features. Here, we combine AAV capsid discovery from nature and rational engineering to report an AAV9 capsid variant, designated as AAV9.HR, which retains AAV9's capability to traverse the blood-brain barrier and transduce neurons. This variant shows reduced transduction in peripheral tissues when delivered through ...

Congenital Heart Defects And Ciliopathies Associated With Renal Phenotypes, George C. Gabriel, Gregory J. Pazour, Cecilia W. Lo

Open Access Articles

Congenital heart disease (CHD) is one of the most common birth defects, and recent studies indicate cilia-related mutations play a central role in the genetic etiology of CHD. As cilia are also known to have important roles in kidney development and disease, it is not surprising that renal anomalies were found to be enriched among CHD mutant mice recovered in a large-scale mouse forward genetic screen. Indeed 42% of mutations identified to cause both CHD and renal anomalies were cilia-related. Many of these cilia mutations comprise cilia transition zone or inversin compartment components, consistent with the known role of these ...

The Comparative Genomics Of Bifidobacterium Callitrichos Reflects Dietary Carbohydrate Utilization Within The Common Marmoset Gut, Korin Albert, Asha Rani, David A. Sela

Open Access Articles

Bifidobacterium is a diverse genus of anaerobic, saccharolytic bacteria that colonize many animals, notably humans and other mammals. The presence of these bacteria in the gastrointestinal tract represents a potential coevolution between the gut microbiome and its mammalian host mediated by diet. To study the relationship between bifidobacterial gut symbionts and host nutrition, we analyzed the genome of two bifidobacteria strains isolated from the feces of a common marmoset (Callithrix jacchus), a primate species studied for its ability to subsist on host-indigestible carbohydrates. Whole genome sequencing identified these isolates as unique strains of Bifidobacterium callitrichos. All three strains, including these ...